Has anyone necked down the 300 RCM case to 6.5 and used a cooler burning powder in it like H1000 with 140 gr bullets?
Would like to hear about it if so.

Google 6.5 extreme. I was going to go that route when I built my SS but decided on the .550" case in the shortened version. So far, I'm glad I did. Bigngreen just posted on the SS with the 160 Matrix at over 3000'.....Rich